The Cal Mag Plus Iron EDDHA is a 2-pound mineral-based supplement that provides fast-release calcium, magnesium, and iron to indoor and outdoor plants. It comes in granules/pellets form and is compatible with flower, all-purpose, and rose plants. The concentrate is designed for hydroponics or soil

1/2 to 1 teaspoon per gallon

2.5 to 5 grams per gallon